1. Field of the Invention
The present invention relates to a rubber boat made of rubber coated fabric and more particularly to a rubber boat mainly used for going down a river.
2. Description of the Prior Art
Conventionally, such a rubber boat has a ring-shaped air barrel composed of a plurality of air chambers of cylindrical configuration in section filled with air, and a boat bottom formed of a bottom cloth which is spread inside of the air barrel at a position higher than the draft level and has a drain port.
Such a rubber boat was developed mainly for fishing or leisure. However, it has been recently employed for going down a river, and especially in a rapid stream, as a large amount of water enters the boat such as by splashing, the boat of the above structure cannot be completely drained. As a larger drain hole for increasing the drain amount causes strength of the bottom cloth to be lowered, the enlargement of the drain hole is limited.